Safety valve for gas burners



Feb. 6, 1931.

C. H. MORROW SAFETY VALVE FOR GAS BURNERS Filed April 16, 1928 ea re. 1

omen H. MORROW, 0F CLEVELAND, OHIO, ASSIGNOR TO THE HOTSTREAM HEATER'CQMPANY, 0F CLEVELAND, OHIO, A CORLPOBATION OF OHIO I SAFETY VALVE FORGAS BURNERS' Application filed April 16,

This invention relates to thermostatic valves for use in connection withgas burners having pilot lights, and the invention has particularapplication to domestic hot water eating installations of the storagetype wherein a pilot light is arranged for normally continuousoperation, a main burner is arranged for intermittent operationdependent on conditions within the hot water tank, the pilot lightserving to ignite gas admitted to the main burner, and being usuallycapable of maintaining water standing in the accomplish the abovedescribed arrangement tank at the temperature to which it has beenraised by the main burner after the same has been shut off 'by thethermostat.

Such a system is illustrated and described more in detail in mycopending application Ser. No. 261,160, filed March 12, 1928.

In such usual installations, should the pilot light he accidentallyextinguished gas may be admitted by the thermostat to the main burner upto the capacity of the supply line and without ignition, resulting in avery dangerous condition in the installation as well as involving acontinuous wastage of gas until the condition is discovered.

The object of my invention is broadly to provide a means for cutting offgas supply to the main burner as the pilot flame is extin uished.

ore particularly m invention comprises the PIOVlSlOIl of asupp ementaryvalve in the main burner line, a pilot flame controlled thermal elementadapted to maintain the suplementary valve open dependent upon comustion at the pilot, the parts being so arranged that the supplementaryvalve is allowed to close as by a spring immediately upon extinguishingof the pilot flame, and whereby the valve will remain closed regardlessof subsequent temperature conditions in the system, until reset to allowreestablishment of the pilot flame.

For this urpose I provide a stop in the casing and inkage cooperabletherewith and associated with the valve and the thermal element, wherebythe valve is maintained open until extinguishing of the pilot flame, thelinkage being arranged to be disassociated how the stop by the elementupon extinction 1928. Serial No. 270,485.

of the flame, whereb the valve is allowed to be closed by the spring,the parts being also so arranged that resetting thereof by hand isnecessary for reassociating the stop and linkage to reopen the valve.

A further object of my invention is, therefore, to so arrange thesupplementary valve and the pilot thermostat control thereof that oncethe valve is closed it cannot be reopened except by hand manipulation ofthe apparatus.

Still another object of the invention is to with the utmost simplicityboth of structure and of operation. A further object of my invention isto provide a structure which combines the functions of pilot burner andpilot thermostat.

The exact nature of the invention together with further objects andadvantages thereof will be apparent from the following descrip-- tiontaken in connection with the accompanying drawings in' which Fig. l is aview in elevation largely in section showing my invention asincorporated in a water heating system of the type described the partsbeing shown relatively positioned as with the pilot burner functioning;Fig. 2 is'a generally vertical section as in the vertical planes. ofline 2-2, Fig. 1; Fig. 3 is a horizontal view as in the planes of line3-3, Fig. 1.

With reference now to the drawings, 1 is a jacket surrounding the hotwater tank of the system; 2 is a casing secured with the jacket 1 as bybolt 3.

The casing 2 has an inlet opening 4 threaded as indicated for connectionwith a ipe 5 through which gas is supplied, pre erably subject to avalve shown diagrammatically at A and thermostatically controlleddependent upon temperature of water in the tank, as by thermostat B. Thecasing 2 also has an outlet opening 6 threaded to receive a pipe 7arranged to deliver gas to the main burner of the system. The casin 2 isalso provided with a wall 8 dividing tl e interior of the casing intotwo chambers: 9 in communication with the supply opening 4 and 10 incommunication with the delivery opening 6. The wall 8 has an opening 11,and a valve 12 is arranged to seat upon the wall 8 to close this openingand thus cut off communication between the supply pipe 5 and thedelivery pipe 7. This valve 12 has a stem portion 13 slidable in a bore14 in a cap 15 which forms a closure for the chamber 9 of the casing. Aspring 16 is arranged in an annular groove in the cap 15 to bear againstthe valve 12 and yieldably urge it to closed position.

The valve 12 has another stem portion 17 projecting into the'chamber 10of the casing.

Extending through the chamber 10 and mounted in the casing 2 for rockingmovement is a shaft 18 which carries without the casing a handle 19 andwithin the casing a split crank 20 secured therewith as by a cotter pin21, the shaft conveniently having the threaded and dead ended casingbearings as indicated. The free end of the crank 20 carries by means ofa pin 22 a link 23. The free end of the link 23 carries a bearing stud24 preferably having a square head; the members 18, 19, 20, 23comprising a linkage as will follow.

Seated for sliding movement in a suitable opening in the casing 2 is arod 25 one end of which is adapted to bear against the head of the stud24. The opposite end of the rod 25 is secured as by the threadedconnection indicated with the outer end of a tubular member 26 whosemedial portion clears the rod 25 to form an annular chamber 27thereabout and whose inner extremity is secured with the casing as bythe threaded connection 28, the tubular member 26 and rod 25 therewithinpassing through a suitable opening in the jacket 1. Adjacent the innerend of the member 26 the casing 2 is counterbored to form an annularchamber 29 which thus communicates with the chamber 27. The

chamber 29 is adapted to be arranged in communication directly with thepipe 5 above the valve A as by piping 30 and a cross bore 31.

The rod 25 near its outer end has a cross bore 32 connecting with alongitudinal bore 33 whereby passage is had from the annular chamber 27to the open extremity of the member 26. L

The members 25 and 26 are of materials having difi'erent coeflicients ofexpansion, that of the member 26, which may be of copper having a highercoeflicient than that of the rod member 25 which may be of iron; so thatthe inner extremity of the member 26 being secured with the casing 2,the outer extremity of the members being secured together and the innerextremity of the member 25 being free to move in the casings theposition of the end of the member 25 extending within the chamber 10 isdependent upon the mean temperature of the two members.

Secured in the casing 2 and extending within the chamber 10 adjacent thestud 24 and corresponding end of the rod 25 is a post 34 having a squareedge immediately adjacent the near edge of the stud.

Operation will be as follows, assuming the pipe 5 in communication witha gas supply, the pilot being lighted and the thermostatic parts,therefore, warm, these conditions being illustrated in Fig. 1. Thespring 16 maintains the valve 12 with its stem portion 17 hearingagainst a heel portion 35 of the link 23. The stud 24 bearing upon thepost 34 limits motion of the stud end of the link 23 to that ofadvancing the stud 24 to bear against the rod 25, this movement beinggenerally about the pin 22 of which is under these conditionssubstantially stationary. The thermostatic elements being warm theposition of the end of the rod element is such that the valve ismaintained open so that gas may flow practically freely through thecasing 2 between the pipes 5 and 7 and thence to the main burner.

Gas passes at all times to the pilot flame by way of the pipe 30 andbore 31; thence through the annular chamber 27, cross bore 32, bore 33and out the open end of the member 26 which thus forms a pilot nozzleoperating independently of the valve A and supplemental valve.

Without the pilot flame the parts 25 and 26 quickly cool and owing totheir different coefficients of expansion the end of the rod 25 projectsincreasingly into the chamber 10 until it pushes the stud 24 from itsposition of rest upon the post 34 which allows the stud to dropdownwardly. This frees the crank 20 allowing the spring 16 to close thevalve rotating the crank in a clockwise direction Fig. 1.

Should the thermostatic valve A thereafter open the supply to the pipe 5the valve 12 will remain seated so that the main burner will receive nogas.

\Vhat I claim is:

. 1. In a device of the class described, agenerally hollow caslng havingan opening adapted for connection with a gas supply line and an openingadapted for connection with a delivery line for a main gas burner, valvemeans in said casing arranged to control communication between theopenings thereof and normally tending to cut off said communication, athermally responsive element associated with said casing, a pilot burnerassociated With said element, said element being movable relative tosaid casing dependent upon maintenance of the pilot flame, link meansarranged in said casing between said valve and said element forcooperation therewith, and a support in said casing for said link means.said link means resting upon said support during maintenance of' saidpilot flame and said valve being thereby held open, said link meansbeing freed from said support by said element upon extinguishment with adelivery line for a main gas burner,

valve means in said casing arranged to control communication between theopenings thereof and normally tending to cut ofl said communication, athermally responsive element associated with said casing, a pilot burnerassociated with said element, said element being movable relative tosaid casing dependent upon maintenance of the pilot flame, link meansarranged in said casing between said valve and said element forcooperation therewith, a support in said casing for said link means,said link means resting upon said support during maintenance of saidpilot flame and said valve being thereby held open, said link meansbeing freed from said support by said element upon extinguishment ofsaid pilot flame, whereupon said valve is allowed to close, and meansfor moving said link means to a position of rest upon said support uponreestablishment of said pilot flame, whereupon said valve is again heldopen.

3. In a device of the class described, a generally hollow casing havingan opening adapted for connection with a gas supply line and an openingadapted for connection with a delivery line for a main gas burner,

valve means in said casing arranged to control communication betweensaid openings thereof and normally tending to close to cut off saidcommunication, a thermally responsive element associated with saidcasing, a pilot burner associated with said element, said element beingmovable relative to said casing dependent upon maintenance of the pilotflame, a crank pivotally mounted in said casing, a link pivotallymounted on said crank and arranged between said valve and said elementfor cooperation therewith, and a able relative to said casing dependentupon maintenance of the pilot flame, a crank pivotally mounted in saidcasing, a link pivotally mounted on said crank and arranged between saidvalve and said element for cooperation therewith, a support in saidcasing for said link, said link resting upon said support duringmaintenance of said pilot flame and said valve being thereby held open,said link being freed from said support by said element uponextinguishment of said pilot flame, whereupon said valve is allowed I toclose, and means for operating said crank to move said link to aposition of rest upon said support upon reestablishment of said' pilotflame, whereupon said valve is again held open.

In testimony whereof I hereby affix my signature.

CLARENCE H. MORROW.

support in said casing for said link, said link resting upon saidsupport during maintenance of said pilot flame and said valve beingthereby held open, said link being freed'from said support by saidelement upon extinguishment of said pilot flame, whereupon said valve isallowed to close.

, 4. In a device of the class described, a generally hollow casinghaving an opening adapted for connection with a gas supply line and anopening adapted for connection with a delivery line for a main gasburner, valve means in said casing arranged to control communicationbetween said openings thereof and normally

